|
|
A007984
|
|
Number of essential graphs with n nodes (in 1-1 correspondence with Markov equivalence classes of acyclic digraphs).
|
|
5
|
|
|
1, 2, 11, 185, 8782, 1067825, 312510571, 212133402500, 326266056291213, 1118902054495975181, 8455790399687227104576, 139537050182278289405732939, 4991058955493997577840793161279
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
REFERENCES
|
S. B. Gillispie and M. D. Perlman, Enumerating Markov equivalence classes of acyclic digraph models, Proc. of Conf. on Uncertainty in Artificial Intelligence (2001), 171-177.
S. B. Gillispie and M. D. Perlman, The size distribution for Markov equivalence classes of acyclic digraph models, Artificial Intelligence, 141 (2002), 137-155.
Bertran Steinsky, Enumeration of Labelled Essential Graphs, Ars Comb., 111, (2013), 485-494
|
|
LINKS
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
David Madigan (madigan(AT)stat.washington.edu)
|
|
EXTENSIONS
|
More terms from Steven B. Gillispie (gillisp(AT)u.washington.edu), Oct 21 2003
a(10) corrected by Steven B. Gillispie (gillisp(AT)u.washington.edu), Aug 14 2007, who says: I have learned from Bertran Steinsky (who determined the correct number) that there was an error in my computer software that computed a(10). The correct value is 1118902054495975181.
|
|
STATUS
|
approved
|
|
|
|